Linear 1D Issue

Burner2k
Burner2k Altair Community Member
edited October 2020 in Community Q&A

I understand that mesh should match between two sets of elements for which 1D connection is desired.

 

I have a scenario here in which I have selected elements for which mesh matches. But still HM shows that element order differs.

 

<?xml version="1.0" encoding="UTF-8"?>05.thumb.PNG.2003b23e573c13b2a2e911f4f640ba71.PNG

 

As shown, I am trying to generate 1D nodes just between sets of elements which have been selected (highlighted by White). I believe in this scenario, HM should create a set of 1D elements.

 

Also what is the alignment referring to? Same question on density. If I chose 2 as density, will there be two elements between each node of top & bottom plates?

 

Another picture showing mesh alignment. Alignment of elements whose edges are darkly shaded.

<?xml version="1.0" encoding="UTF-8"?>04.thumb.PNG.38775c7d20da7c05ded0d3d079ae6e6c.PNG

 

If I have set of surfaces which have dissimilar meshes, then I have to create individual 1D elements manually? Currently no option in HM to create automatically?

 

Thanks...

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Answers

  • tinh
    tinh Altair Community Member
    edited August 2018

    Hi

    Press F1 to know how to use that panel

  • Simon Križnik
    Simon Križnik Altair Community Member
    edited August 2018

    Hi Burner2k,

     

    this happens to me too sometimes, when it fails to connect.

    It helps to isolate only the elements/nodes to be connected and pick the alignment nodes away from the boundary.

     

    The meshes do not have to match exactly, as long as the elements are equal in type (tria, quad) and distribution (quantity in different directions). In other words, nodes can be perturbed.

     

    Alignment nodes can be seen as a frame of reference between meshes. You are right about density.

     

     

  • Burner2k
    Burner2k Altair Community Member
    edited August 2018

    Hi Ivan,

    Thanks for the response. I have a couple of follow up questions. 

     

    >> It helps to isolate only the elements/nodes to be connected and pick the alignment nodes away from the boundary.

     

    Could you please elaborate more on the isolating the elements part? Should I create a new component for these elements? Also, as shown via pictures in my original post, I do believe, I have same type of elements (they are actually plot shell elements...no property assigned yet) and the selected bunch of top & bottom elements match exactly in distribution. 

     

    >> Alignment nodes can be seen as a frame of reference between meshes.

    Frame of reference for what? 1D elements? I guess, one way to learn is to try it out. https://filefox.cc/z9us5wjz2k0a/01227_Young_Girlfriend_blow_n_ride.mp4

     

    Tinh, the help via F1 is unfortunately not very clear on what alignment refers to. 

  • Simon Križnik
    Simon Križnik Altair Community Member
    edited August 2018

    By isolate I mean you should only have the elements to be connected visible by using mask panel.

     

    Alignment nodes are used to identify congruent features on both meshes, because currently Hypermesh can not automatically recognize mesh pattern to be connected. If for example there are two identical meshes but one is rotated then you should help HM map 1D elements between by specifing some reference nodes.

    There is analogy to pattern repetition optimization in Optistruct, wherby local coordinate systems are defined for each group of elements.

     

    You probably should edit/delete the link ;)/emoticons/default_wink.png' srcset='/emoticons/wink@2x.png 2x' title=';)' width='20' />

     

     

     

  • Burner2k
    Burner2k Altair Community Member
    edited August 2018

    Ivan, thanks for your support. After selecting alignment nodes, 1D elements were created.

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